<html>
  <head>
  </head>

  <div class="container">
    <div class="item">嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿嘿</div>
    <div class="item">哈哈</div>
    
</div>
<style>

/* https://blog.csdn.net/china_coding/article/details/128379721 */
  .container {
         width: 200px;
         display: flex;
         border: 2px dashed crimson;
  }

 .item:first-child {
    width: 80;
    
     flex:1;
 }
 .item:last-child {
    width: 80;
   
     
 }
</style>

</html>